The present invention relates generally to self-propelled, ground-working vehicles such as lawn mowers and, more particularly, to operator control systems for use with the same.
Various types of lawn mowers are known. For example, small, walk-behind mowers are in general use by both homeowners and professionals alike. At the other end of the spectrum are large, riding mowers adept at mowing correspondingly large and typically unobstructed areas. Between these two categories lies what are commonly referred to as xe2x80x9cmid-sizexe2x80x9d mowers.
Generally speaking, mid-size mowers are self-propelled units having a cutting width of approximately 36-60 inches. While they may be configured as either riding (including ride-on and ride-behind) or walk-behind units, walk-behind mowers potentially offer greater maneuverability. For example, walk-behind mowers are particularly efficient when mowing large lawns having numerous obstacles (e.g., trees, shrubs, flowerbeds, and the like) which necessitate intricate trimming, or when mowing lawns which may otherwise be ill-suited to high-speed riding mowers. Moreover, walk-behind mowers are often used in areas with steep slopes which may pose traction or tipping problems for riding mowers. Furthermore, mid-size, walk-behind mowers are also, in general, less expensive than riding mowers. While the present invention is directed to control systems for use with either riding or walk-behind vehicles, it will, for the sake of brevity, be described with respect to mid-size, walk-behind mowers.
One type of control system known for use with mid-size mowers uses two rearwardly extending handles each equipped with a scissors-type lever. Each lever operatively controls one of two drive wheels typically located at or near the rear corners of the cutting unit. Where the levers are configured as xe2x80x9cnormally engaged,xe2x80x9d actuating (e.g., squeezing) one of the drive levers causes disengagement and/or braking of the corresponding drive wheel, permitting the mower to turn about that wheel. Alternatively, the levers may be xe2x80x9cnormally disengagedxe2x80x9d such that actuating (e.g., squeezing) one of the drive levers causes engagement of the corresponding drive wheel.
While scissors-type lever control systems are more than adequate for their intended purpose, drawbacks remain. For instance, scissors-type levers, in general, may provide limited mechanical advantage in overcoming lever tension. Accordingly, when cutting a lawn with many trees, shrubs, or other obstacles that necessitate numerous turns, discomfort in the hands, wrists, and arms may occur. Scissors-type lever control systems may also be susceptible to variation in lever tension over the lever travel. Furthermore, depending on the position of each lever within its throw, the operator may not be able to grasp the respective lever with all fingers.
Other systems are also known. For example, U.S. Pat. No. 5,511,367 to Powers et al. and U.S. Pat. No. 5,809,755 to Velke et al. disclose control systems having a generally transverse hand position. While addressing some of the above-identified problems, other issues with hand position and/or control actuation potentially remain.
Control systems of the present invention seek to overcome the above-identified drawbacks by providing operator control systems that combine natural hand positioning with conveniently located drive control levers. Control systems in accordance with the present invention further provide a hand position interior to the control system to reduce potential contact between the operator""s hands and external objects during operation. The drive control levers of the present invention may additionally provide substantially constant tension throughout their range of motion, resulting in drive control lever forces which are more evenly distributed throughout the operator""s hands.
In one embodiment, an operator control system for a self-propelled vehicle is provided. The control system includes a handle assembly having a first hand grip and a second hand grip, wherein the first hand grip and the second hand grip extend generally upwardly and towards one another when the vehicle is in an operating configuration. The system further includes a first control lever associated with the first hand grip, wherein the first control lever is pivotable about a first pivot axis. Preferably, the first pivot axis is substantially parallel to a first grip axis of the first hand grip. A second control lever associated with the second hand grip is also included. The second control lever is pivotable about a second pivot axis, wherein the second pivot axis is substantially parallel to a second grip axis of the second hand grip.
In another embodiment, an operator control system for a self-propelled lawn mower is provided having a handle assembly including a first hand grip defining a first grip axis and a second hand grip defining a second grip axis. The first grip axis and the second grip axis generally approach one another above the handle assembly when the mower is in an operating configuration. The system also includes a first control lever associated with the first hand grip, where the first control lever is pivotable about a first pivot axis, the first pivot axis being substantially parallel to the first grip axis. A second control lever associated with the second hand grip is also included. The second control lever is pivotable about a second pivot axis, wherein the second pivot axis is substantially parallel to the second grip axis.
In yet another embodiment, an operator control system for a self-propelled, walk-behind or ride-behind lawn mower is provided. The control system includes a handle assembly having a first hand grip having a first grip axis and a second hand grip having a second grip axis. The first grip axis and the second grip axis generally intersect above the handle assembly when the mower is in an operating configuration. Further, the first hand grip and the second hand grip each form ends of the handle assembly. A first control lever associated with the first hand grip is also included wherein the first control lever is pivotable about a first pivot axis. Further, a second control lever associated with the second hand grip is provided wherein the second control lever is pivotable about a second pivot axis. The first pivot axis is substantially parallel to the first grip axis and the second pivot axis is substantially parallel to the second grip axis.
The above summary of the invention is not intended to describe each embodiment or every implementation of the present invention. Rather, a more complete understanding of the invention will become apparent and appreciated by reference to the following detailed description and claims in view of the accompanying drawings.